1. Field of the Invention
The present invention relates to a riding lawn tractor equipped with two hydrostatic transmissions (to be referred to as HSTs), wherein one of the HSTs is provided for speed and the other is for steering. Additionally, the present invention relates to a riding lawn tractor having a compact and durable drive system for drive wheels and mower.
2. Related Art
It is known to equip vehicles with two HSTs, located to the right and left of the vehicle, for each drive wheel. Each HST has an axle shaft that joins an HST and a drive wheel and individually drives a drive wheel according to an angle of the swash plate in the HST. When the drive wheels are powered in unison speeds, the vehicle goes straight, and when powered in different speeds, the vehicle turns. This requires each drive wheel to be powered equally for going straight. Therefore, this requires fine tuning. Additionally, the different capacity of the hydrostatic motors or/and pumps between the right HST and the left HST can cause odd control feelings and not easy control. U.S. application Ser. No. US2002/0007980A1 was shown to improve that. It shows a vehicle having two transmission devices with HSTs, which are driven by the transmission devices. Therefore, it is hard and expensive to drive a mower deck simply for a small vehicle with the transmission devices.